The national fraternity Theta Chi is suing Stanford University and various groups associated with the former co-op Chi Theta Chi for allegedly infringing on Theta Chi’s trademarked name and symbols.

Theta Chi’s 163-pagelawsuit, filed March 18, charges all defendants—which include the University, the Stanford Board of Trustees, the Alumni Association of Chi Theta Chi, its Boards of Directors and its president Thomas Allison— with trademark violation, misleading advertising, trademark dilution and unfair competition. The suit also implicates unnamed residents of 576 Alvarado Row.

Theta Chi maintained a chapter at Stanford, called Alpha Epsilon, from the 1920s until the 1980s. According to Theta Chi’s lawsuit, the national fraternity disowned the Alpha Epsilon chapter in 1998 due to “lack of membership and improper conduct by residents of the House.”

Soon afterward, ex-members of the all-male Alpha Epsilon formed the independent group Chi Theta Chi—or XΘX, in reference to their status as “Ex-Theta Chi’s”—and began to run a co-ed “cooperative house” (co-op) of the same name.

Since the 1998 split, Theta Chi has sought to erase all association with its former Stanford branch.

Theta Chi took its first legal action on the issue in October of 2012, when the fraternity sued students and alumni managing Chi Theta Chi for infringing on its trademark. The result was a January 2013 settlement with the Alumni Association of Chi Theta Chi House, in which the Alumni Association agreed to cease using names and marks that might suggest national affiliation, including “Chi Theta Chi.” The settlement made exceptions for certain usages such as historical description.

Stanford “informally offered to Theta Chi Fraternity to support the settlement,” wrote Stanford spokesperson Lisa Lapin in an email to The Daily.

Not long before the settlement, in 2012, the University acquired the Chi Theta Chi House after decliningto renew the Alumni Association’s lease while citing health and safety concerns about the House’s management. As part of Stanford’s support for the settlement, Lapin said, the University renamed the residence576 Alvarado Row.

According to Theta Chi, Stanford assured the fraternity in 2013 that it would remove various references to “Chi Theta Chi” including an online campus map and a construction fence around the co-op.

But with this month’s new lawsuit, Theta Chi has reopened its legal battle, alleging that the Alumni Association broke terms of the settlement and continued to illegally co-opt Theta Chi’s name.

The lawsuit also claims that the University has “steadfastly worked to undermine Theta Chi’s efforts to protect its marks,” by knowingly allowing references to Chi Theta Chi to persist in University-owned news outlets and webpages, and by allowing residents of 576 Alvarado Row to host events such as “Theta Chi Thursdays.”

The lawsuit goes on to state that Theta Chi spoke with both Alumni Association and University representatives earlier this year about renewed concerns.

Theta Chi claims that the Alumni Association admitted this January to breaching the 2013 settlement by failing to file for dissolution as stipulated. Theta Chi also points to the association’s 2013 and 2014 tax returns, filed under the name “Alpha Epsilon Alumni Association of Theta Chi.”

Regarding the University, Theta Chi states that during a Jan. 27 phone call, Stanford legal representatives admitted to previous knowledge of continued use of the Chi Theta Chi name. However, Lapin said the University denies this claim.

“To Stanford’s knowledge, there are no current references to Chi Theta Chi on any Stanford websites other than to reference the term in a historic manner,” Lapin said.

But Theta Chi has moved forward with their litigation.

“We are disappointed by this lawsuit,” said Robert Phillips, counsel for the Alumni Association. “Theta Chi is complaining about minor, legacy use of the ‘Chi Theta Chi’ name by students. That use is reasonable, and expected, given that ‘Chi Theta Chi’ was the name of the co-op for nearly 30 years.Regardless, Theta Chi agreed that the Alumni Association is not responsible for use of the former name by students. Theta Chi also agreed that the Alumni Association can make fair use of the co-op’s former name. The Alumni Association intends to defend the case and expects to prevail.”

Similarly, Lapin told The Daily that the University is “surprised and disappointed” with Theta Chi’s decision to sue.

“We are hopeful that working with Theta Chi Fraternity and our students we will be able to resolve this matter expeditiously,” she wrote.